package ch10;
public class EncryptAndDecrypt {
	String encrypt(String sourceString,String password) {
		char p[] = password.toCharArray();
		int n = p.length;
		char c[] = sourceString.toCharArray();
		int m = c.length;
		for(int k=0;k<m;k++) {
			int mima = c[k]+p[k%n];
			c[k] = (char)mima;
		}
		return new String(c);
	}
	String decrypt (String sourceString,String password) {
		char p[] = password.toCharArray();
		int n = p.length;
		char c[] = sourceString.toCharArray();
		int m = c.length;
		for(int k=0;k<m;k++) {
			int mima = c[k]-p[k%n];
			c[k] = (char)mima;
		}
		return new String(c);
	}
}
